This invention relates to systems and methods for producing bidirectional power conversion. More specifically, this invention relates to circuits and methods for creating a truly bidirectional power converter with multiple control loops and power routing.
As the need for smaller and more intricate integrated circuits surfaces, so does the need for smaller power routing and power conversion processes. Power routing and power conversion processes may be found, for example, in uninterruptible power systems, next-generation automotive electrical systems, redundant battery systems for computers, telecommunications equipment and portable electronic devices.
Bidirectional power conversion provides the ability to change power attributes to and from a component. Bidirectional power conversion may be found in portable devices such as cell phones and Personal Digital Assistants (PDAs) that contain rechargeable batteries. These DC rechargeable batteries are automatically charged when connected to an AC power source. During battery charging, the power from the AC power source is converted into DC power (either externally with a wall adapter or within the portable device circuitry), and the battery is charged. Additionally, during battery charging, the portable device operates using the power supplied from the AC power source. When the portable device is not connected to the AC power source or wall adapter, the battery serves as the primary power source. This process of supplying power to and receiving power from the battery is in accordance with the principles of bidirectional power conversion. Furthermore, the process of routing power from the DC battery instead of the AC power source or wall adapter is present in such systems.
In prior systems, truly bidirectional power conversion is not realized. Instead, prior systems perform bidirectional power conversion through two separate unidirectional power converters and an additional power routing system to switch between the two converters. Each separate unidirectional power converter is dedicated to the power conversion process associated with a particular direction. The result of using multiple power converters in addition to additional logic for the purpose of routing in prior systems is that the amount of switches present is inopportunely large.
In light of the foregoing, it would be desirable to provide a truly bidirectional power converter with multiple control loops and power routing in order to reduce the complexity, size and cost associated with current converters that utilize multiple unidirectional power converters.